To study the effects of eucaryotic transcription factors on normal and abnormal cell growth and differentiation it is essential to know their primary structure. Knowledge of the amino acid sequence enables the investigator to design oligonucleotide probes and specific antibodies to study the distribution and effects of these factors. Transcription factors and their associated proteins will be purified to homogeneity by polyacrylamide gel electrophoresis and transferred to protein binding membranes. Proteolysis with trypsin will be performed on these membrane-bound proteins. Fragments will be separated by reversed phase high pressure liquid chromatography and subjected to Edman degradation. The partial amino acid sequence obtained this way can then be used to isolate and characterize the gene coding for this factor. The entire amino acid sequence can then be deduced from the gene sequence. The proposed studies will improve the understanding of the regulation of cell growth and differentiation at the molecular level.